High rates of early dropout from out patient drug free (ODF) programs and subsequent relapse are critical issues for substance abuse treatment. Motivational interventions to address this have shown effectiveness in alcoholism treatment. This study would extend development of such interventions in three ways: by demonstrating a new group Motivational Interventional (GMI) as an option to existing individual motivational therapy; by testing the efficacy of this group model as an induction to standard ODF treatment rather than as a free-standing treatment; and by extending such motivational interventions from primary alcoholics to drug users (cocaine, opiates, cannabis). The specific aims and methods of the study are: 1) To implement a new Group Motivational Intervention as an induction to standard outpatient treatment. The intervention will employ the motivational elements of effective brief therapies (FRAMES) in a group setting. GMI consists of a total of four twice-weekly, manual-driven, small group sessions with the objectives of helping patients identify and understand their ambivalence about substance use, treatment and recovery. 2) To conduct an efficacy trial of GMI, by contrasting drug-abusing patients voluntarily randomly assigned to two conditions: (a) GMI followed by outpatient treatment "as usual" (N=120), and (b) outpatient treatment "as usual" (i.e., direct admission to clinic-based outpatient treatment) (N=135). The primary outcome variables are length of retention in treatment and substance use at 3 and 6 month follow-ups. 3) To determine the patient characteristics and treatment process variables which may predict drop-out and other differences in treatment outcomes. Key variables to be examined will include: sociodemographics, criminal involvement, treatment history, substance abuse severity, psychiatric severity, consequences of substance abuse, motivation for change, self- efficacy, therapeutic alliance, group treatment climate, "autonomy supportiveness" of treatment, types and amounts of services, received, 12- step involvement, and social support. 4) To conduct a cost-effectiveness analysis of GMI. Because even a brief group therapy may add to treatment costs, it is important6 to determine the cost per patient for each additional unit of positive outcome achieved (assuming outcomes improve).